Synchronous motor for driving clocks and the like



Jan. 13, 1931. F. TOEWE 1,783,813

SYNCHRONOUS MOTOR FOR DRIVING CLOCKS AND THE LIKE' Filed Aug. 2, 1929 INVENTOR Fna'fz To ewe I BY I ATTORNEY P'atented Jan. 13, 1931 l UNITED yn-Es PATENT or fice rmz roawx, or mnmeinr, Gamay,

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- KIIIEIII'ZLE TAXAMETEB UND APIABATE A. OF VILLINGEN, GERMANY, A CORPO- RATION' OI GERMANY SYNOHBONOUS Moron ron nnrvme' cnocizs am) 'rnn 1.11m

Application filed August 8, 1929, Serial lo.

1 My ,invention relates to improvements in a synchronous motor for driving clocks and the like and it consists in the novel features,

' which are hereinafter more fully described.

avoid the use of several exciter windings and statorsteel laminations, which are at resent in "use in synchronous motors and which are not suitable for economical mass production.

l Another object of my invention is to rothe synchronous motor, one form 0 is illustrated in the accompanying drawings or by anyme- .20 chan'ical equivalent or obvious modification ofthesame.

In the preferred form or embodiment of my invention Idispose field poles of the same sign only in the correct pole distribution on 2 'both sides of a plane of symmetry; -I also preferv to divide the stator laminations them- )selves according to this plane 'of symmetry with the result that uniform stampings.

. In the drawings,

' Figs. 1. and 2 are dis.

trations of the fields of istribution of six 'pole and ten (pole fields respectively; and

Fig. 3 is a of a 6 ole synchronous motor.

agrammatic view in elevation In Flg. 1, the field, which is representedby-th'e tillCle a, is divided for a fi-pole'rotor or, in other words,'6-field poles are to be spaced, withalternatingsigns, at equal dis- 0 tances apart on the ci-rcinnference of the circle a; If a motor of this ty is connected with an A. 0. supply of shaft would turn 1000 R.

I According to this invention, -a'plane of 4 symmetry is disposed through the field,in-

dicated bythe line A-B. On the left side of A B a pole. S?) has been eliminated, likewise to the rig t a le (N)'of opposite sign has been eliminate with the result that on I0 each of thertwo sides ofthe plane of synperiods, the motor One of the objects of my invention is to from one another.

I f of the other pole S of W.

stator is divided according to the p ane of symmetry A-B with the result that the stator laminations N, S are of exactly the the stator consists of v coils h, thereby obtaining a Fe'rraris rotat-' mmatical I illus -ture m, 'a si 882,883, and 1,. Germany August 12, ms.

metry are always two poles (N, N) or S, S, of the same sign. They are located in the correct pole distribution, i. e. the poles of even sign follow each other at a distance of two pole divisions, while the oles of oppo site sign are only one pole 'vision apart Fig. 3 shows a stator according to the mode of distribution of Fig. 1. The stator surrounds a 6-part synchronous rotor b with 4 pole pieces 0, d, e, f. The pole pieces '0 and dare made up from the one pole N of the exciter winding W and the ole pieces 0 and he core of the same form.

It is clearly evident that "the novel ar'-. rangement of themulti-polarfield insures an especially cheap construction of the-stator.. J

- In the case of self-starting synchronous motors, in which the rotor receives his starting. in ulse by means of an additional-rothe poles with the well known shielding ing field.

n the case of clocks which are driven by A. C. motors, use is often made of the natural stray-field ofthe field magnet, in order to release, by means of an additional arma-' al or even an auxilia clockwork, shoul ,for some reason or at er, the line voltage fail to work. For the purpose of obtainin a stray-field as. active as possi- .73 tary fie, d, it is of advantage tosplit the field .poles c, d, e, f, and to provide each half of w ble, 2 ole ugs i and k are provided on the pole pieces'd and e, see Fig. 3, the desired straylng field being produced between these pole-lugs.

As may vention may also be u n a synchronous motor of any desired number of poles, for

beseen'fromsliil'g. 2, the present I I.

instance 10 poles. ,Inthis case 3 poles of the 1 same sign are disposed on both sides of the plane of symmetry A-B and also obey the above described law as to the correct pole distribution. Also here, the stator of thissynchronous motor is of extremely simple construction, the stator laminations conslsting of stampings of uniform shape.

Variations are possible and parts of my invention may be used without other parts. 1

I do not, therefore, restrictmyself to the details as shown and described, but I intend to include also all mechanical equivalents and obvious modifications of the same, within the scope of my invention.

I claim as my invention, and desire to secure by Letters Patent:

1. In a synchronous motor, a laminated stator consisting of appropriate plates formed with core bars and field-poles, said core bars being divided on the central vertical axis of said stator, said field poles being arranged in symmetry at opposite sides of said axis, the poles of each half of said stator being separated two pole distances, and the adjacent poles of the opposite halves of said stator being separated by a single pole distance.

2. In a synchronous motor, a rotor, a laminated stator consisting of a core bar and a plurality of field-poles; said core bar being divided on the central vertical axis of said rotor and stator; said field-poles beinfg arranged in symmetry at op osite sides 0 said axis, all poles of each halFof said stator being separated two pole distances, the adja-' cent poles of the opposite halves of said stator being separated but a single pole distance, and an exciter winding for operating said rotor.

3. In a synchronous motor, a rotor; a: stator conslstlng of acore bar and a lurality of field poles, said core bar being 'vided on the vertical axial line of said rotor and stator, said field-poles being arranged in symmetry at opposite sides of said axlal line and being centrally split; the poles at one side of said axial line being of one sign,

while the poles at the opposite side of said line being of opposite si ;the poles of even sign followin .each ot er two, pole s aces apart, while t e poles of opposite sign ing but one winding or operating said rotor. q

4. In a synchronous motor, a stator consisting of plates of appropriate material, each plate being constituted by duplicate halves, each halfbeing formed with a component half of a core bar, and a plurality of split poles spaced-two normal pole distances apart, and perforations to receive binding bolts 5. In combination, a stator, a rotor and an exciter winding; said stator consisting of a core bar, a plurality of split field-poles, and'pole lugs at the, bottom thereof, an-armature operating between said lugs; said core bar being divided on the'vertical axial line of said stator, rotor and armature, said field-poles on each halfof said stator being ole space apart, and an -exciter spaced two normal ole distances apart and the adjacent oles oi opposite halves ofsaid stator being apart.

6. In a s chronous motor, a multi-polar stator consisting of two similar parts each part having a pluralit of split poles two pole distances apart, t e adjacent poles of opposite parts "of said stator being one pole distance apart. 1

7. In a synchronous motor, a rotor having polar projections, and a multi-polar field, the circular series of field poles consisting of equal numbers of equal signs, said field-poles also being unequally spaced around said rotor, and an exciter winding to operate said rotor.

8. In a synchronous motor, a two part ut one normal pole distance multi-polar stator, each-part having poles v of equal signs, the normal distance between the even sign poles being twice as great as the normal distance between the oles of op osite signs, for the purpose set orth.

Signed at Stuttgart, Germany, this 19th day of J11ly,A. D. 1929. i

, FRITZ TOEWE. 

